Estimation of system reliability in Brownian stress-strength models based on sample paths

Reliability of many stochastic systems depends on uncertain stress and strength patterns that are time dependent. In this paper, we consider the problem of estimating the reliability of a system when bothX(t) andY(t) are assumed to be independent Brownian motion processes, whereX(t) is the system stress, andY(t) is the system strength, at timet.This research was partially supported by the Air-Force Office of Scientific Research Grants AFOSR-89-0402 and AFOSR-90-0402.     

A measure of discrimination between two residual life-time distributions and its applications

A measure of discrepancy between two residual-life distributions is proposed on the basis of Kullback-Leibler discrimination information. Properties of this measure are studied and the minimum discrimination principle is applied to obtain the proportional hazards model.Northern Illinois University on a professional development leave.     

Remarks about the Inviscid Limit of the Navier–Stokes System

In this paper we prove two results about the inviscid limit of the Navier-Stokes system. The first one concerns the convergence in H ^s of a sequence of solutions to the Navier-Stokes system when the viscosity goes to zero and the initial data is in H ^s . The second result deals with the best rate of convergence for vortex patch initial data in 2 and 3 dimensions. We present here a simple proof which also works in the 3D case. The 3D case is new.     

On the reliability of stochastic systems

In this note we consider the problem of computing the probability R(t₀ = P(X(t) > Y(t) for 0 < t ? t₀), where X(t) and Y(t) are stochastic processes. This extends some of the existing results to the case of stochastic processes. Related estimation problems are also considered.     

Nonstandard topologies with bases that consist only of standard sets

Let be an infinite set, a set of pseudo-metrics on and If is limited (finite) for every and every then, for each we can define a pseudo-metric on by writing st We investigate the conditions under which the topology induced on by has a basis consisting only of standard sets. This investigation produces a theory with a variety of applications in functional analysis. For example, a specialization of some of our general results will yield such classical compactness theorems as Schauder's theorem, Mazur's theorem, and Gelfand-Philips's theorem.

     

Thermally Induced,Nonlinear Vibrations of Rotating Disks

The natural frequency and responses for the nonlinear free vibration ofheated rotating disks are presented analytically when nonuniformtemperature distributions pertaining to the laminar and turbulentairflow induced by disk rotation are considered. The nonuniformtemperature distributions on the disk are highly dependent on itsrotation speed. The natural frequencies for symmetric and asymmetricresponses of a 3.5 inch diameter computer memory disk are calculated.When the disk is heated, its stiffness becomes larger for the two lowestnodal diameter numbers and smaller for the other nodal diameter numbers.It implies that the vibration of heated, rotating disks for the highernodal diameter numbers may be induced more easily than the cooled one.The results for the nonlinear vibration can reduce to those for thelinear vibration when the nonlinear effects vanish. To furtherinvestigate of the interaction of thermal and nonlinearity of rotatingdisks, the temperature distribution for such a rotating disk needs to bedeveloped.     

TRIPHENYLPHOSPHINE-MEDIATED CHEMOSELECTIVE SYNTHESIS OF FUNCTIONALIZED SPIRO-IMIDAZOL-4-ONES

Stabilized phosphoranes, obtained from the three-component reaction between dialkyl acetylenedicarboxylates and spiro-hydantoins in the presence of triphenylphosphine, undergo a smooth intramolecular Wittig reaction in boiling toluene to produce functionalized spiro-imidazol-4-ones in good yields.